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#include <bits/stdc++.h>

using namespace std;

set<pair<int, int>> bricksList;
unordered_map<int, bool> bricksAt[210001];
unordered_map<int, int> active[210001];
int n, m, k, q;
int number = 0;

int offset = 1000;

// bool checkSolid(int x, int y)
// {
//     if (bricksAt[x + 1][y] && bricksAt[x + 1][y + 1] && bricksAt[x][y + 1]) return true;
//     if (bricksAt[x + 1][y] && bricksAt[x + 1][y - 1] && bricksAt[x][y - 1]) return true;
//     if (bricksAt[x - 1][y] && bricksAt[x - 1][y + 1] && bricksAt[x][y + 1]) return true;
//     if (bricksAt[x - 1][y] && bricksAt[x - 1][y - 1] && bricksAt[x][y - 1]) return true;
//     return false;
// }

bool canTake(int x, int y)
{
    if (!active[x + 1][y] && !active[x - 1][y]) return true;
    if (!active[x][y + 1] && !active[x][y - 1]) return true;

    return false;
}

void dfs(int x, int y)
{
    if (!bricksAt[x][y]) return;
    if (canTake(x, y))
    {
        active[x][y] = false;
        ++number;
        if (active[x + 1][y])
            dfs(x + 1, y);
        if (active[x - 1][y])
            dfs(x - 1, y);
        if (active[x][y + 1])
            dfs(x, y + 1);
        if (active[x][y - 1])
            dfs(x, y - 1);
    }
}

void put(int x, int y)
{
    bricksAt[x][y] = true;
    active[x][y] = true;
    bricksList.emplace(x, y);
    // ++number;
    // dfs(x, y);
}
void remove(int x, int y)
{
    bricksAt[x][y] = false;
    active[x][y] = false;

    bricksList.erase(make_pair(x, y));
    // dfs(x + 1, y);
    // dfs(x - 1, y);
    // dfs(x, y + 1);
    // dfs(x, y - 1);
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    cin >> n >> m >> k >> q;

    for (int i = 0; i < k; ++i)
    {
        int x, y;
        cin >> x >> y;
        x += offset; y += offset;

        bricksAt[x][y] = true;
        active[x][y] = true;
        bricksList.emplace(x, y);
    }

    for (auto [x, y] : bricksList)
    {
        if (active[x][y])
            dfs(x, y);
    }

    cout << number << '\n';

    for (int i = 0; i < q; ++i)
    {
        int x, y;
        cin >> x >> y;
        x += offset; y += offset;

        if (bricksAt[x][y])
        {
            remove(x, y);
        }
        else
        {
            put(x, y);
        }

        number = 0;

        for (auto [x, y] : bricksList)
        {
            if (bricksAt[x][y])
                active[x][y] = true;
        }

        for (auto [x, y] : bricksList)
        {
            if (active[x][y])
                dfs(x, y);
        }

        cout << number << '\n';
    }
}